This invention relates to railcar trucks and more particularly involves a method for preassembling a bolster with friction shoes fitted therein, the improved assembly of a bolster with friction shoes and improved bolster and shoe components therefore.
A typical railcar truck comprises wheelsets mounted on two axles which support side frames at each side of the railcar and a transverse bolster extending between the side frames with the ends thereof supported on load springs carried by each side frame between two vertical friction plates. Usually a truck is located under each end of a railcar and the car itself is pivotally supported upon a centerplate centrally positioned on each bolster. Thus the weight of the railcar will cause the ends of the bolsters to move vertically on the load springs while confined between the friction plates.
To provide proper damping for the suspension system, friction shoes are located in pockets to each side of the bolster adjacent the side frame friction plates. The friction shoes have vertically disposed friction faces which contact the friction plate. In certain types of such friction shoes there is a shoe slope surface, generally opposite the friction face, which declines from a top portion of the friction shoe to a bottom portion thereof and away from the friction face and which engages a bolster slope surface on the inside of the pocket. The latter type shoe also has a bottom opening or hole through which a control spring extends from the bolster to the top portion of the shoe. The control spring urges the friction shoe against the bolster slope and upwardly through the pocket, while the slope also guides the shoe outwardly against the vertical friction plate.